Mostly, current tools are abysmal at maxing the semantic capacity. Midjourney is great a generating things that look good, but terrible at piecing scenes together.
Recent example I tried: a robot playing magic the gathering seated across a human.
Even getting the human in the picture is a challenge, but then the model doesn't know enough about MTG (it correctly pattern matches to "board game" or "card game").
Some pictures generated are much better than other, and it would be great to take e.g. the table setup from one picture and the robot from another, but doing is not really possible atm ("blend" doesn't work for that).
I have no doubt this will improve, but I'm wondering if there's something underlying this that could be a more general limitation? Maybe simply not enough data (a google image search for magic the gathering is also pretty disapppointing).
Another example: a glowing blue <company logo> carved into a stone monolith. It sometimes got the logo to be carved (rarely), it was never glowing blue (usually the whole monolith, or a part of it).